Area Forecast Discussion
Issued by NWS Oklahoma City, OK

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
540
FXUS64 KOUN 191648
AFDOUN

Area Forecast Discussion
National Weather Service Norman OK
1048 AM CST Sun Feb 19 2017

.UPDATE...
Adjusted precipitation/weather through the afternoon.

&&

.DISCUSSION...
Starting to see a donut hole area of clearing centered over
Wichita Falls and spreading across western north Texas. Coverage
of fog remains well spread across the region, but visibilities
are expected to slowly improve through noon, so the dense fog
advisory will be allowed to expire at 11 AM CST.

Adjusted precipitation chances, removing mention through noon,
and breaking up the afternoon into two 3 hour blocks. Moisture
advection continues to increase, steadily, with low 60s dew points
already building from north Texas into southern Oklahoma. After
discussing with SPC, it`s beginning to look like initiation may
start a little earlier, around 3 PM CST. Current trends support
this, the clearing and increasing dew points in western north
Texas. Additionally, the last few runs of the RAP have picked up
on these trends. To quote SPC, "not a traditional spring set up
by any stretch," with the surface low lifting east/northeast out
of Colorado into Nebraska this evening. However, the combo of
modest CAPE values, increasing low level jet, and focus along en
elongated frontal boundary, severe thunderstorms are possible,
especially across portions of western north Texas and the southern
half of Oklahoma. Hail will be the primary threat, as low level
winds through the mid to late afternoon are supportive of deep
layer shear of 40 to 50 kts. Additionally, latest short range
guidance has continued to reveal window of backing surface winds
across north Texas into southern Oklahoma, increasing low level
helicity values in a narrow window, ending around sunset. With
this in mind, expect initial development to be supercellular in
nature, with an low risk of tornadoes with the strongest storms
not out of the realm of possibility. However, storms are expected
to quickly become linear and more of a convective mess through
the evening hours.

Kurtz

&&

.PREV DISCUSSION... /issued 559 AM CST Sun Feb 19 2017/

UPDATE...
As moisture (50 degree dewpoints) cont to move north and west
into areas that had cooled into the 40s have seen more widespread
dense fog develop. Will therefore go ahead and issue a dense fog
advisory for much of northern and western OK through much of the
morning hours.

PREV DISCUSSION... /issued 535 AM CST Sun Feb 19 2017/

AVIATION...
Widespread IFR/LIFR conditions this morning with only a gradual
improvement by this afternoon, mainly with visibilities. Ceilings
will remain IFR or lower MVFR category throughout the day. Showers
and thunderstorms will impact most sites late today and tonight.
Should see VFR conditions develop after 06Z tonight across west and
move toward I-35 corridor by end of forecast period.

30

PREV DISCUSSION... /ISSUED 324 AM CST Sun Feb 19 2017/

DISCUSSION...
Widespread low clouds and fog will likely continue across much of
the area through the morning hours before the fog lifts and some
breaks in the clouds form. However, as we go through the afternoon
hours we should see a gradual increase in showers and
thunderstorms, especially to our west and southwest as larger
storm system begins to move out into the Plains.

Main forcing will move over the area tonight and expect to see a
broken line of storms develop and move east across much of the
eastern two-thirds of Oklahoma, including western north Texas.
Sufficient instability will develop for a few strong to perhaps
severe storms, mainly I-40 southward late this afternoon through
this evening. Still appears that as the system moves east it will
slow as southern part of trough develops a closed low across
northern Texas. This will allow some heavier rainfall to possibly
occur across southeast Oklahoma, however heaviest amounts should
be confined to areas south and east of our area.

Dry and warm to very warm weather is then expected through much of
the upcoming week with an increase in fire weather concerns,
especially by late in the week. Another storm system will move
into the central U.S. by Thursday, but will have very little
moisture to to produce precip. However, very warm temperatures and
strong, gusty winds will create elevated to perhaps critical fire
weather conditions across parts of the area. On the back side of
the system, cooler temperatures are expected by Friday, but dry
and windy conditions will continue.

&&

.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK  69  57  73  43 /  40  80  10   0
Hobart OK         66  51  72  40 /  40  50  10   0
Wichita Falls TX  69  55  74  44 /  50  70  10   0
Gage OK           71  46  72  36 /  20  40  10   0
Ponca City OK     69  58  72  42 /  20  70  20   0
Durant OK         70  60  70  49 /  20  80  50  10

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...Dense Fog Advisory until 11 AM CST this morning for OKZ004>023-
     034-035.

TX...None.
&&

$$

04/03



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.